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26-431: Anapo's political platform has been labeled as left-wing. Nonetheless, Anapo made it clear that they differ from Communists regarding the rights of private property. The party's political height grew during the mid-to-late 1960s and the beginning of its decline came in 1970, after what is commonly perceived as its zenith by historians. It was founded in 1964 by a group of politicians led by Gustavo Rojas Pinilla , who left

52-590: A sidereal compass rose of a sidereal compass. [REDACTED] Media related to Zenith (topography) at Wikimedia Commons Culmination In observational astronomy , culmination is the passage of a celestial object (such as the Sun , the Moon , a planet , a star , constellation or a deep-sky object ) across the observer's local meridian . These events are also known as meridian transits , used in timekeeping and navigation , and measured precisely using

78-543: A transit telescope . During each day, every celestial object appears to move along a circular path on the celestial sphere due to the Earth's rotation creating two moments when it crosses the meridian. Except at the geographic poles , any celestial object passing through the meridian has an upper culmination , when it reaches its highest point (the moment when it is nearest to the Zenith ), and nearly twelve hours later,

104-440: A culmination and the next is a sidereal day , which is exactly 24 sidereal hours and 4 minutes less than 24 common solar hours , while the period between an upper culmination and a lower one is 12 sidereal hours. The period between successive day to day (rotational) culminations is effected mainly by Earth's orbital proper motion , which produces the different lengths between the solar day (the interval between culminations of

130-645: A fact accepted by the political mainstream in Colombia as of 2005, specifically due to the gradual surfacing and historical evaluation of supporting evidence, memoirs and testimonies. Initially, ANAPO tried to declare the elections illegitimate, both by actively calling for a citizen protest or uprising, and also by demanding that Colombia's Electoral Court abstain from supporting the official result. The Court denied this request and recognized Misael Pastrana as president elect. ANAPO's reaction created alarm in many National Front politicians and media outlets, who supported

156-547: A much smaller impact on sidereal observation, impacting Earth's climate through the Milankovitch cycles significantly more. Though at such timescales stars themself change position, particularly those stars which have, as viewed from the Solar System , a high proper motion . Stellar parallax appears to be a similar motion like all these apparent movements, but has only from non-averaged sidereal day to sidereal day

182-466: A slight effect, returning to its original apparent position, completing a cycle every orbit, with a slight additional lasting change to the position due to the precessions. This phenomenon results from Earth changing position on its orbital path. From the tropics and middle latitudes , the Sun is visible in the sky at its upper culmination (at solar noon ) and invisible (below the horizon) at its lower culmination (at solar midnight ). When viewed from

208-438: Is at the zenith only if it is directly overhead. In a scientific context, the zenith is the direction of reference for measuring the zenith angle (or zenith angular distance ), the angle between a direction of interest (e.g. a star) and the local zenith - that is, the complement of the altitude angle (or elevation angle ). The Sun reaches the observer's zenith when it is 90° above the horizon, and this only happens between

234-473: Is followed by a lower culmination , when it reaches its lowest point (nearest to the Nadir ). The time of culmination (when the object culminates) is often used to mean upper culmination. An object's altitude ( A ) in degrees at its upper culmination is equal to 90 minus the observer's latitude ( L ) plus the object's declination ( δ ): Three cases are dependent on the observer's latitude ( L ) and

260-520: The Old French cenith , zenith first appeared in the 17th century. The term zenith sometimes means the highest point , way, or level reached by a celestial body on its daily apparent path around a given point of observation. This sense of the word is often used to describe the position of the Sun ("The sun reached its zenith..."), but to an astronomer, the Sun does not have its own zenith and

286-468: The Tropic of Cancer and the Tropic of Capricorn . In Islamic astronomy , the passing of the Sun over the zenith of Mecca becomes the basis of the qibla observation by shadows twice a year on 27/28 May and 15/16 July. At a given location during the course of a day, the Sun reaches not only its zenith but also its nadir , at the antipode of that location 12 hours from solar noon . In astronomy ,

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312-431: The declination ( δ ) of the celestial object : The third case applies for objects in a part of the full sky equal to the cosine of the latitude (at the equator it applies for all objects, because the sky turns around the horizontal north–south line; at the poles it applies for none, because the sky turns around the vertical line). The first and second case each apply for half of the remaining sky. The period between

338-635: The region within either polar circle around the winter solstice of that hemisphere (the December solstice in the Arctic and the June solstice in the Antarctic ), the Sun is below the horizon at both of its culminations. Supposing that the declination of the Sun is +20° when it crosses the local meridian, then the complementary angle of 70° (from the Sun to the pole) is added to and subtracted from

364-475: The ANAPO formed a splinter group called Broad Colombian Movement (Movimiento Amplio Colombiano, abr. MAC) which soon joined the left-wing National Union of Opposition. In 1974, the 19th of April Movement (M-19), a Colombian guerrilla group, came into the public scene and claimed that its struggle was a reaction to what it called the illegitimacy of the 1970 elections, the nation's bipartisan political system, and

390-732: The Conservative Party of Colombia. The year of 1970 saw the electoral defeat of its presidential candidate, the former dictator General Gustavo Rojas Pinilla , at the hands of the Conservative candidate of the National Front, Misael Pastrana Borrero , after a close April 19 election which ANAPO and several prominent figures of Colombian public opinion condemned as fraudulent at the time. The accusation has been maintained by ANAPO and most opposition parties ever since. Polls have shown that subsequently it has almost become

416-508: The National Front agreement that had supported them. Initially, the M-19 hoped to actively incorporate ANAPO leaders and party members as its political representatives, but many, including ANAPO chief Maria Eugenia Rojas , ultimately rejected any attempt to actively establish such an association. After the political reform of 2003, it disappeared entirely, joining a coalition of leftist parties known as Polo Democrático Independiente that became

442-450: The Sun) and the sidereal day (the interval between culminations of any reference star ) or the slightly more precise, precession unaffected, stellar day . This results in culminations occurring every solar day at different times, taking a sidereal year (366.3 days), a year that is one day longer than the solar year , for a culmination to reoccur. Therefore, only once every 366.3 solar days

468-411: The altitude in the horizontal coordinate system and the zenith angle are complementary angles , with the horizon perpendicular to the zenith. The astronomical meridian is also determined by the zenith, and is defined as a circle on the celestial sphere that passes through the zenith, nadir, and the celestial poles . A zenith telescope is a type of telescope designed to point straight up at or near

494-481: The announced result. President Carlos Lleras Restrepo vehemently denied the charges of fraud and argued that his responsibility was to hand over power to the legally recognized winning candidate. The government declared a state of siege in order to try to stop riots from erupting, signs of which appeared mainly in Bogotá but also in some other regions of the country. In 1972, a group of National Congress deputies from

520-528: The celestial sphere. The word zenith derives from an inaccurate reading of the Arabic expression سمت الرأس ( samt al-raʾs ), meaning "direction of the head" or "path above the head", by Medieval Latin scribes in the Middle Ages (during the 14th century), possibly through Old Spanish . It was reduced to samt ("direction") and miswritten as senit / cenit , the m being misread as ni . Through

546-414: The culmination reoccurs at the same time of a solar day, while reoccurring every sidereal day. The remaining small changes in the culmination period time from sidereal year to sidereal year is on the other hand mainly caused by nutation (with a 18.6 years cycle), resulting in the longer time scale axial precession of Earth (with a 26,000 years cycle), while apsidal precession and other mechanics have

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572-409: The declination of the star equals the latitude of the observer. If the current time at Greenwich is known at the time of the observation, the observers longitude can also be determined from the right ascension of the star. Hence "Zenith stars" lie on or near the circle of declination equal to the latitude of the observer ("zenith circle"). Zenith stars are not to be confused with "steering stars" of

598-606: The observer's latitude to find the solar altitudes at upper and lower culminations, respectively. From most of the Northern Hemisphere , Polaris (the North Star) and the other stars of the constellation Ursa Minor circles counterclockwise around the north celestial pole and remain visible at both culminations (as long as the sky is clear and dark enough). In the Southern Hemisphere there

624-415: The political party Polo Democrático Alternativo in 2005. Zenith The zenith ( UK : / ˈ z ɛ n ɪ θ / , US : / ˈ z iː n ɪ θ / ) is the imaginary point on the celestial sphere directly "above" a particular location. "Above" means in the vertical direction ( plumb line ) opposite to the gravity direction at that location ( nadir ). The zenith is the "highest" point on

650-442: The station, relative to the earth. Zenith stars (also "star on top", "overhead star", "latitude star") are stars whose declination equals the latitude of the observers location, and hence at some time in the day or night pass culminate (pass) through the zenith. When at the zenith the right ascension of the star equals the local sidereal time at your location. In celestial navigation this allows latitude to be determined, since

676-590: The zenith, and used for precision measurement of star positions, to simplify telescope construction, or both. The NASA Orbital Debris Observatory and the Large Zenith Telescope are both zenith telescopes, since the use of liquid mirrors meant these telescopes could only point straight up. On the International Space Station , zenith and nadir are used instead of up and down , referring to directions within and around

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